Editing Limit state design (section)

==Example treatment of LSD in building codes==
The following is the treatment of LSD found in the [[National Building Code of Canada]]:

 NBCC 1995 Format
 φR > α<sub>D</sub>D + ψ γ {α<sub>L</sub>L + α<sub>Q</sub>Q + α<sub>T</sub>T}

 where φ = Resistance Factor
       ψ = Load Combination Factor
       γ = Importance Factor
       α<sub>D</sub> = Dead Load Factor
       α<sub>L</sub> = Live Load Factor
       α<sub>Q</sub> = Earthquake Load Factor
       α<sub>T</sub> = Thermal Effect (Temperature) Load Factor

Limit state design has replaced the older concept of [[permissible stress design]] in most forms of [[civil engineering]]. A notable exception is [[transportation engineering]]. Even so, new codes are currently being developed for both geotechnical and transportation engineering which are LSD based. As a result, most modern buildings are designed in accordance with a code which is based on limit state theory. For example, in Europe, structures are designed to conform with the [[Eurocode]]s: [[Steel]] structures are designed in accordance with [[EN 1993]], and [[reinforced concrete]] structures to [[EN 1992]]. Australia, Canada, China, France, Indonesia, and New Zealand (among many others) utilise limit state theory in the development of their design codes. In the purest sense, it is now considered inappropriate to discuss [[safety factor]]s when working with LSD, as there are concerns that this may lead to confusion. Previously, it has been shown that the LRFD and ASD can produce significantly different designs of steel gable frames.<ref>Katanbafnezhad, Naser, & Hoback, Alan, S. (2020). Comparison of LRFD and ASD for Pre-Fabricated Gable Frame Design, American Journal of Engineering Research (AJER), vol. 9(5), pp. 120–134.</ref>

There are few situations where ASD produces significantly lighter weight steel gable frame designs. Additionally, it has been shown that in high snow regions, the difference between the methods is more dramatic.<ref>Katanbafnezhad, Naser, & Hoback, Alan, S. (2020). Pre-Fabricated Gable Frame Design in High Snow Regions- Comparison of LRFD and ASD, American Journal of Engineering Research (AJER), vol. 9(6), pp. 160–168.</ref>